Posts by Sandtreader
70 posts • joined Monday 22nd June 2009 11:18 GMT
Posted in WTF is... WebRTC?
Flash?
Just thinking... Could support for uncooperative browsers (IE!) be provided with a Flash app using the Camera/Mic access and implementing the WebRTC protocols over a raw socket?
Empty gestures
New gestures:
To delete the current file, scrumple up screen and toss in recycling bin.
To shred the current file, rip screen in half or set light to it
To archive current file, spike on sharp vertical spike on desk (HSE's nightmare)
To e-mail current file, folder screen, put in in envelope and hand deliver to recipient
To decrypt current file, soak screen in benzene and hold over a light source
...
... or possibly "minimum".
Re: Trusting trust
On further investigation:
https://groups.google.com/forum/?fromgroups=#!topic/mozilla.dev.security.policy/aqn0Zm-KxQ0
https://freedom-to-tinker.com/blog/sjs/turktrust-certificate-authority-errors-demonstrate-the-risk-of-subordinate-certificates/
It looks like the intermediates/subordinate CA certs that were issued were *not* their standard ones, so other customers wouldn't be effected. That still leaves the issue of the whole system only being as strong as its weakest branch, though.
Re: Trusting trust
If the intermediates that were wrongly released (more accurately, private keys revealed) were their standard ones in current use then revoking them will indeed revoke "some or all" of the certificates previously issued. So although they could in theory reissue a new intermediate and carry on, there's a good chance every one of their current customers will be baying for blood, never mind the browser developers wanting bits of their anatomy on skewers. Ouch.
But as others have said, every time this happens it shows the weakness of a distributed authority system where any branch can pretend to be any other branch. Proper integration with the domain system which provides firewalls between branches is the only solution.
Horses for Courses
I'm working with some other schools in Cornwall on developing proper Computer Science / Programming teaching to replace the godawful Office-based GCSE ICT. We're taking a twin-track approach:
1) Scratch (probably up to year 8) and GreenFoot (year 9 and above) to teach proper programming on existing ICT suites - both can be installed by the ICT tech in a few minutes, and completely free.
2) Raspberry Pi to enable all kinds of 'physical computing' projects in DT, Physics, Biology, Chemistry, Sports... Probably using only one or two devices for each project, not a classroom full.
So I agree with the article, I can't see the need for a suite of RPi's lined up in rows, it has far more value as a component for tinkering in the real world. What it has done, though, is lit up the entire debate and pulled things like Scratch and GreenFoot (which have existed quietly for years) into the limelight - all good.
Re: Lack of Use (If Any) and Lack of Knowledge (If Any)
OK, leaving aside the fundamental impedance mismatch between touch and desktop UI metaphors, we geeks could probably hold our noses, learn to configure away the worst bits of it and set it up so it is vaguely usable again, because after a lifetime of it we're used to reconfiguring our brains and spending hours tweaking to adapt to badly designed products
That's not the point. The point is the vast majority of users are like your "older lady" and we are going to have to support them. That is a sword of Damocles hanging over the IT world and everyone except Microsoft and a few gadget freaks knows it.
Festering hacks, endlessly copied and pasted...
Not a great article, but El Reg journalism isn't *that* bad.
Needless obsolescence
No, the primary argument is making hundreds of millions of FM radios - in cars, homes, phones, building sites - needlessly obsolescent overnight, for no benefit whatsoever.
The switch to digital TV made sense because it gave a massive improvement in quality, TV is mostly a full-attention medium where people care about quality, the devices were renewing anyway (CRT to LCD) and most households have only one or two of them. Radio is entirely different. DAB quality improvement is hotly debated; radio is for most people a background medium in a noisy environment, the devices don't require any upgrade and many households have lots of them. I count about 7 in mine, of which 4 are in active use (two cars, one phone, one wind-up portable).
DAB does have its place (where it works) for fixed installations for audiophiles. Fine, let them have it. But for 95% of users its completely unnecessary and because of the power and quality issues, a retrograde step.
... and don't even get me started on the death of truly local radio due to the bigger advertising regions.
Missing the point about RISC
The most important point about RISC isn't arguments about instructions per second, but reduced die size. The original ARM-2 had 30,000 transistors, roughly the same as the 8-bit 6502. That makes it (a) cheap (b) low power (c) easily testable and (d) easily integrated.
Wood yard?
Don't you mean an 8km drive to the wood 0.9144m?
Cat-o-ten-tails? Shiver me timbers!
Cat-o-nine-tails are made by unlaying twice-laid 3-strand rope, me hearties. Neither man nor Devil can make a cat-o-ten-tails.
Shades of ML
OK, he says it isn't type provable (it can't be because it allows 'any' types) but there's a lot of really nice ML-like type inference going on here.
As someone whose main gripe with JS is lack of types leading to runtime failure I think this could be a real boon - but I'd want it the same code completion & inference tricks in Eclipse, please!
Posted in Famous thesps tread boards on smart TVs
Macbeth! Macbeth! Macbeth!
The superstition over mentioning Macbeth only applies if you are inside the theatre at the time...
Pekoe
Orange + T, clearly.
Posted in New MPEG format paves the way for UHDTV
Re: The critical measure here is the bit rate
>> Where are you going to find space for 90Mb/s, or even 25Mb/s, signals without returning the UK to a three channel country?
Multicast IPTV over GPON Fibre
Re: (Slightly) longer term view
Fair point about the annual mean trend. You should be able to get the summer minimum trend with from: 1979.6 / every: 12 / trend but this doesn't work, it forgets the expanded scale. I'll add it to the bug list!
(Neat trick using every:12, BTW, hadn't thought of that myself!)
Paul, WFT
(Slightly) longer term view
Looking at the Sea Ice extent over 30+ years puts ice-free in the summer somewhere around 2100 - *if* the present trend continues.
http://www.woodfortrees.org/plot/nsidc-seaice-n/plot/nsidc-seaice-n/scale/plot/nsidc-seaice-n/trend/plot/nsidc-seaice-n/trend/offset:-5
Yet another use for Fimo
... but Rameses(.*)'s comment above does make me think that a *very* slightly oblate circle would make quite a good security head, since copy-moulding tolerances aren't that great and any slop would make it slip.
ASSERT_FALSE("C++" == "C#");
(and I shall go to my grave saying C-hash, so there!)
Re: Wrong idea, wrong place
I don't mind the idea of a gym or play area, since in both cases these folk are deliberately wasting energy for other reasons (fitness, being three), so some of it is potentially trappable - particularly in a spinning gym where it's directly available as a circular motion (cue Charlie Brooker, as someone else has already hinted at).
But the idea of putting this on roads is as ludicrous as the idea a couple of years ago of putting wind turbines in the central reservation. You would essentially be forcing cars to roll uphill all the time, even on a flat road. This would just burn more fossil fuels, hugely less efficiently than just putting diesel in a generator, never mind the astronomical energy and financial cost of building the thing.
Someone will no doubt now suggest it would be OK if they were electric cars...
Re: Energy calculations.
Oh, on the 7W thing... A rival firm Powerleap claims 5Ws (5J) per step. So I'm guessing the journo or subbie changed 7Ws to 7 Watts.
It also adds up with the claim that 5% of energy is enough to light the luminaire in the tile itself. Assuming it lights for 1 sec test gives you 0.5W of LEDs - about the same as a medium-sized torch, so fair enough.
Enough now. Mines the one with the wind-up torch in the pocket.
Re: Energy calculations.
Oh yes, *: I'm assuming 'several hundred' is 400 because less it would be 'a few' and 500 or more it would be 'NEARLY HALF A MEGAWATT-HOUR!!!'
Re: Energy calculations.
Looked at another way, 4e5 Wh (*) over 1e4 hrs/yr is about 40 W average power. Allowing a duty cycle of 25% (say 6 hours use in darkness per day), and some storage (one 100 Ah leisure battery would do it), that gives you 160W of lighting. Say 20 small CF or LED fittings. Actually to light that particular piece of walkway, I guess that's doable.
The other issue is where this energy comes from. The pedestrians were relying on the hardness of the floor to reflect energy for the next step. Take that away and like walking on sand it requires more energy. Given the nature of the place let's assume it comes from increased consumption of sugary drinks. That comes from sugar beet in the UK, in a process that involves input of lots of embedded energy in fertilisers, plus direct input to dissolve and recrystallise in the factory, not to mention transport and packaging. So even leaving aside the capital energy cost of building the tiles, it could even be negative on a revenue basis...
Energy calculations.
(warning, from memory and in head, so could be very wrong!)
Ok, so 4e7 visitors generate (say) 4e5 Wh, that's 1e-2 Wh per visit = 36J
Assuming average visitor mass 50kg (in Stratford?), dropping from a height of 0.1m, PE = mgh = 50J. Assume no losses to air friction (no wing suits, only shell suits), KE on impact = 50J. Assume no way to capture take-off energy, 50J per footstep.
Tiles are 60cm wide, assume walkway about 6m wide, you could have a double row and capture 2 footsteps per entrance and exit, 4 footsteps in all = 200J.
So conversion efficiency required = 36/200 = 18%. I guess that's not outlandish, even it was a simple alternator driven from a rack-and-pinion gear. No idea of the efficiency of piezo electric...
Which is not to detract from the fact that 4e5 Wh is a pathetic amount of energy in the first place...
Terminology
Something doesn't add up in the terminology here: "Card information was salted and hashed". What use is a hashed credit card number, either to Bad Guys or indeed to the service itself? More likely they were symmetrically encrypted and the passphrase stored in the filesystem somehow. That does at least mean that the DB replicating backups are not sensitive in themselves.
The problem of how to protect information in the DB, private keys etc. from a root attacker is always a tricky one. You could demand entry of the passphrase at startup but that prevents unattended restart, and in theory a really determined attacker could get it out of memory if they can get access to the running daemon.
Of course the trick is to avoid getting rooted in the first place... When your hosting provider demands your root password, refuse, quoting this story!
Posted in Ten... freeware gems for new PCs
Piriform
Genius name for a company making fixing-Windows-cruft utilities. Blimey, Fred, it's all gone piriform!
Re: IBM ROMP vs. ARM
MUL & MLA were indeed slow when both sides of the multiplication were variable, but lots of multiplies have a constant one one side, often sparse in bits (e.g. 2^N - 8, 16, 256 - or 2^N+2^M - 10) and the great trick (of ARM assembler hackers like me, and the - at the time - brilliant Norcroft compiler) was to unfold the multiply into shift-adds (one per bit) using the barrel shifter, one cycle each.
One my most treasured possessions is an original ARM-1 dot-matrix instruction set description with CONFIDENTIAL scrawled over it in red ink...
Destruction of negative feedback mechanism
Gaia and the Global Warming issue are both all about feedbacks, negative or positive. The (relative lack of) warming in the last decade or so would tend to indicate one or more of:
a) The scary positive feedbacks which Hansen et al were warning about in the 1990's either don't exist or haven't triggered yet
b) Negative feedbacks exist which weren't recognised before (clouds?)
c) The apparent pause is just the bottom end of a cycle (e.g. PDO) and abnormal service will be resumed shortly.
I think Lovelock got scared by (a), and temporarily forgot (b), which is the basic premise of his whole Gaia idea.
*But*, and this is a big but, one of the things he pointed out at a talk a few years back which resonated with me is that we are systematically destroying the mechanisms of negative feedback - forests in particular. That to me means we need to focus back on all those traditional Green issues such as deforestation, soil loss, pollution and population control - many of which are also good carbon reduction strategies just in case the positive feedback folk are right after all...
Point of order, my Noble Lords
That it was my Lord McNally who furnished the response; my Lord Sharkey posited the question.
(can't get Laurie Anderson out of my head though; paging Lord Sharkey, white courtesy telephone please.)
A Turing test...
... in which the investigator is able to ask a number of questions of a Noble Lord to ascertain if there is any sign of intelligence within.
But seriously, folks, even as a lifelong fan of Turing (it's not just computing - check out what he did for developmental biology) and a strong believer in gay rights, I'm in two minds about this pardon business. I agree with JGC on why he couldn't support the second petition:
http://blog.jgc.org/2011/11/why-im-not-supporting-campaign-for.html
But I think there's also an important semantic difference between a pardon and apology - it seems to me the apology is the stronger response.
A pardon *could* be read as "OK, you *were* guilty of gross indecency, you nasty little sodomite, but because you did all this other cool stuff we'll rather pointlessly let you off". Whereas the apology quite clearly says "OK, we can't undo the past, but we do recognise that the law at the time was abhorrent".
So the pardon *could* still exist in a system in which the law at that time is still considered valid and moral now, and his (supposed) moral guilt for homosexuality is just outweighed by his other gifts to society. The apology is stronger because it unambiguously and entirely transfers any guilt (vicariously) to the government of the time.
Does this make any sense?
domains are case insensitive
DNS is case-insensitive and the fborigin.com whois entry is lowercase like every other domain. Where does this bizarre casing idea come from?
Gaia FTW
So forests have (yet another) mechanism for creating global homeostasis that they (and we) need to survive. Maybe we should stop cutting them down, then...
I just don't buy it
Even if you could either break the encryption/signature/frequency hopping, or apply microscopic delays in such a way as to fool it into thinking its distance from one or more satellites was greater, we're not talking about just randomly buggering it up, we're presumably talking about getting it to land the right way up, wheels down, somewhere soft.
Insufficient security of control systems or operator finger trouble all sound infinitely more plausible than a GPS hack.
OK, you win the prize for best C fragment - encompassing both C and UNIX concepts in a wistful wrapper - nice one!
Metric = Google
OK, scrap that - here is the definition of the Tiobe metric:
http://www.tiobe.com/index.php/content/paperinfo/tpci/tpci_definition.htm
Basically counting search results on +"<language> programming"! Worthless, surely? What's the betting C will spike next month?
Well, here's my contribution to the index in roughly cronological order:
BBC Basic programming ARM Assembler programming C programming C++ programming Javascript programming
Thanks for the link, that's really interesting. It appears they are counting people-popularity (number of engineers, courses etc.) rather than LOC, projects or whatever. Interesting to see how C# has stolen quite a bit of Java's fire, leaving C almost back at pole position.
But I wonder if this might favour old and university-course languages. For example, (who (uses-p `LISP)) any more??
Most popular language? By what metric?
I keep reading that C is the second most popular language, and some suggestion that the most popular is Java. Based on LOC, I guess. That seems a little unfair since C is one of the world's least verbose languages and used in situations which demand a small amount of code running extremely quickly and reliably.
Shouldn't the count be of number of instances of the software running? In which case, count a handful of instances of Tomcat for each corporate Java project and hundreds of millions for every embedded device, phone, TV, car dashboard, router, GPS (...) running a C-based RTOS or Linux.
And what are Java VMs written in, anyway?
Aerosols = old news
The cooling effect of aerosols has been known for ages - it's the conventional explanation for the post-war cooling. But aerosols have a very short lifetime compared to CO2 - so the real question is what happens when the Chinese get fed up with smog and/or run out of coal...
Watch this graph...
You can watch it happen (or not happen) here:
http://www.woodfortrees.org/plot/pmod
(PMOD = measurement of total solar insolation)
http://www.woodfortrees.org/plot/sidc-ssn/from:1975
(Sunspot number)
I think both indicate something slightly different is happening...
Two wrongs don't make a right
The implied logic of the article (explicitly stated by some commenters) is that there is no point the EU doing anything to improve efficiency and increase renewable capacity because China is heading in the opposite direction.
This is wrong both ethically and practically:
Ethically because someone else's worse evil doesn't justify your own.
Practically because China will one day catch up and need to use (and potentially buy from us) all that energy-efficiency and renewable technology that we've developed.
PV energy payback < 4 years
Not this old canard again. The energy payback time for PV solar is at worst 4 years and is falling with new technology.
http://www.nrel.gov/docs/fy04osti/35489.pdf (PDF)
NPOV?
"C++ and Java require statements being terminated with a
’;’. Both Scala and Go don’t require that. Go’s algorithm
enforces certain line breaks, and with that a certain coding
style. While Go’s and Scala’s algorithm for semicolon
inference are different, both algorithms are intuitive and
powerful."
I don't think that would pass Wikipedia review... One might argue that inference of syntactic elements from whitespace is ugly and error prone, and enforcement of K&R style doubly so - unless you do it properly and get rid of braces altogether, like Python. Adding semis is like breathing, you don't even know you're doing it; so why mess with it?
Also, in terms of conciseness, it hardly seems fair to compare ISO C++ with something brand new like Scala and Go: Why not C++0x, which instantly gets rid of the lot of the verbosity with 'auto'? And Scala's fancy for comprehension structure was the first thing they threw out when optimising it!
Open access?
The key question here - as Christian Berger and an AC both alluded to above - is how open this is. i.e. how are mere mortals able to inject multicast traffic into their network. It would be great if it was fully routed but I'd lay money it is source-specific and hence pretty much only available if you're plugged into their core routers (= if you're BT or a major ISP).
Done properly this could not only enable IPTV - a multicast fileshare carousel, for example, is far, far more efficient than dozens of unicast connections into a CDN for the same file.
Posted in BT and EE join together for Cornish LTE
2Mb/sec (which is a lot when you're in Cornwall) - until tomorrow!
We already have Superfast pilot areas in Cornwall running with FTTC at 40Mbit/sec; full rollout with FTTP and FTTC to be announced tomorrow - see superfastcornwall.org, Twitter #sfcornwall.
That's a fib
No, fib() is only called once. It's the function it returns, called 'f' in main() which is called repeatedly, modifying a and b each time.
Reaching closure
It's a long-winded way of doing Fibonacci but a nice-ish way of demonstrating closures. The fib() function doesn't actually do anything, it returns a function which can be asked to do so something later. a and b act rather like globals and are held in a 'closure' attached to the function object returned by fib(). Each call of this function (which gets assigned to 'f' in the main()) modifies a and b. The double assignment is a trick to calculate both right-hand sides before assigning them to new values of a and b, which gives you a kind of two-element queue, which is what you need for calculating Fibonacci. HTH.
Language enforces K&R shock
Oh damn, I was getting interested until you said that. So "ANSI" bracing is out? C syntax may not be optimal but it is automatic to millions of programmers...
Posted in Save the planet: Stop the Greens
Energy payback time for a modern turbine = 3 months
http://guidedtour.windpower.org/media(444,1033)/The_energy_balance_of_modern_wind_turbines%2C_1997.pdf
